PARK CITY, Utah (AP) — The Sundance Film Festival is all about the shared experience of the theater, so imagine the surprise of realizing that one of the most moving films at this year's fest most moving films is something that can only be seen inside of an Oculus Rift headset.

"Dear Angelica " is a 12-minute illustrated story about memory, movies and grief that premiered at the Festival last Friday. In the film, a girl, voiced by Mae Whitman, lies in bed writing a letter to Angelica (Geena Davis), a famous movie star who we also discover was her mother. We swirl around in her memories of Ange...